Over the last years, the Internet of Things (IoT) has grown in protocols, implementation and use cases. Regarding to communication protocols, the Constrained Application Protocol (CoAP) has started to gain some momentum as it follows the REST paradigm, it is very lightweight and it can be embedded in constrained device and networks. There are several available open source libraries that implement CoAP, that target different platforms and written in different programming languages. Each of these libraries has its own features and requirements and therefore, it is very important to select the most appropiate one for each proyect or system. The aim of the work carried out in this proyect has been to help developers choose the library that suits better each system. To do that, a preliminary research has been done on libraries, they have been theoretically analyzed and finally some "demos"have been developed. After analyzing the features and extensions each library supports, the "demos"have been executed to measure some important parameters such as latency and memory and CPU consumption, in a concrete hardware. With this analysis and measurements, the goal of helping developers select the correct library for their system has been targeted. Finally, a paper has been written and submitted to an international conference.